This invention relates to optical-to-electrical and electrical-to-optical modules.
More particularly, the present invention relates to optical-to-electrical and electrical-to-optical modules that are radially symmetrical about a longitudinal axis.
And more specifically the present invention pertains to optical-to-electrical and electrical-to-optical modules that incorporate a lens system, along with the radially symmetrical features that compensate for temperature changes.
In optical-to-electrical and electrical-to-optical (hereinafter xe2x80x9coptoelectricxe2x80x9d) modules used in the various communications fields, one of the problems that must be solved is the efficient transmission of light between a light generating device and an optical fiber or, alternatively, the transmission of light from the optical fiber to a light receiving device without being affected by temperature changes and the like. Here, it will be understood by those skilled in the art that the term xe2x80x9clightxe2x80x9d is a generic term that includes any electromagnetic radiation that can be modulated and transmitted by optical fibers or other optical transmission lines.
Here it will be understood that the optoelectric modules are used to communicate between an optical fiber and an optoelectric device, such as a light source (e.g. a laser, light emitting diode, etc.) generally referred to as a transmission module, or between an optical fiber and a light receiving device (e.g. a photodiode, PIN diode, PN diode, etc.) generally referred to as a receiving module. In this disclosure both modules are referred to generically as optoelectric modules.
Generally, one of the problems with optoelectric modules is the amount of time and effort required in the fabrication and assembly. Another problem that arises is that much of the time and effort in assembly and mounting is applied in alignment of the various components so that light generated by, for example a laser, reaches the core of an optical fiber and light emanating from an optical fiber must be directed onto a photo diode or the like. After substantial time is expended in the original alignment procedures, temperature changes and the like during operation can substantially change the alignment and cause substantial changes in the amount of light being usefully applied. These changes can substantially affect the continued operation of the modules.
It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art.
Accordingly, it is an object the present invention to provide new and improved radially symmetrical optoelectric modules.
Another object of the present invention is to provide new and improved radially symmetrical optoelectric modules that further incorporate a novel lens systems so that expansion and/or contraction during changes in temperature does not affect alignment.
Another object of the present invention is to provide new and improved radially symmetrical optoelectric modules that are easily aligned and assembled.
Another object of the present invention is to provide new and improved radially symmetrical optoelectric modules that remain aligned during changes in operating temperature.
And another object of the present invention is to provide new and improved radially symmetrical optoelectric modules that improve the efficiency of optical systems.
Still another object of the present invention is to provide new and improved radially symmetrical optoelectric modules that allow the use of a variety of components and component materials.
Briefly, to achieve the desired objects of the present invention in accordance with a preferred embodiment thereof, provided is a radially symmetrical optoelectric module including a symmetrical ferrule defining an axial opening extending along an optical axis and having first and second ends positioned along the optical axis. The ferrule is formed radially symmetrical about the optical axis with a lens assembly engaged in the ferrule along the optical axis. A first end of the ferrule is formed to receive an optical fiber such that an end of the optical fiber is positioned along the optical axis and adjacent the lens assembly and light passing through the optical fiber is acted upon by the lens assembly and an optoelectric device is affixed to the second end of the ferrule so that light traveling along the optical axis appears at the optoelectric device.
In a preferred embodiment, the radially symmetrical optoelectric module includes a receptacle assembly with a symmetrical ferrule and a first lens. The ferrule defines an axial opening extending along an optical axis and has first and second ends positioned along the optical axis. The ferrule is formed radially symmetrical about the optical axis and the first lens is engaged in the ferrule along the optical axis. The first end of the ferrule is formed to receive an optical fiber such that an end of the optical fiber is positioned along the optical axis and adjacent the first lens with light passing through the optical fiber being acted upon by the first lens. An optoelectric package includes an optoelectric device and a second lens positioned adjacent the optoelectric device, the second lens is mounted along the optical axis by the optoelectric package. The optoelectric package is affixed to the second end of the ferrule so that light traveling along the optical axis appears at the optoelectric device and passes through the second lens. Because of the xe2x80x9ctwo lens systemxe2x80x9d axial spacing of the structural components is not critical and because of the combination of radial symmetry and the two lenses, the module expands and contracts equally in all directions during changes in temperature so that alignment is not affected and the module provides a constant output under varying conditions.